The Research Of Microwave Photonic Devices Based On Microring Resonator

Complex signal processing functions is difficult realized directly in the RF field，microwave photonics was first presented in1993, which attracted increasingly attentionof scholars from various countries. It can use the inherent characteristics of microwavephotonic devices to realize complex signal processing functions in the microwave andmillimeter wave domain. In the optical signal processing system, the notch filter is avery important device, and is a key element to achieve tunable filter, reduce systemcosts. Another important device-microwave photonic phase shifter is an important partin microwave applications, such as phased array antenna and biomedical detectionsystem. Therefore, the development of microwave photonic devices has brought a newrevolution for optical communications, microwave photonics and integrated opticsresearch has become a hot topic in recent years.First, the theoretical basis of microring resonators is reviewed. The opticalwaveguide theory is derived from Maxwell’s equations, coupling region between thecircular waveguide and the straight waveguide is analyzed in detail. All-pass micro-ringresonator parametric model is derived to obtain the transfer function of light intensity,performance parameters of filter is analyzed. Micro-ring resonator with small size,simple structure is particularly suitable for large-scale monolithic integration. Thisthesis presents an all-pass micro ring resonator based on SOI, with radius of only1.5m, and the all-pass micro-ring resonators was verified by FDTD methodsimulation.The notch filter based on all-pass microring resonator was designed. At first, thefilter characteristics and those three parameters:(coupling length, width of thewaveguide and coupling coefficient) which affect its performance is analyzed in detail.In single-mode waveguide transmission, corresponding different effective refractiveindex of the waveguide was simulated. After the structural parameters were optimized,an all-pass micro-ring notch filter with normalized extinction ratio over36dB,bandwidth of3.4nm, and FSR over72nm was realized.Last, the basic principle of micro-ring resonator phase shifters is in-depthresearch. Fineness curve was used to characterize the three states for coupling region:the critical coupling, under-critical coupling and over-critical coupling. Different phase shift curve with OptiFDTD was numerically simulated. Finally, full360°phaseshift was achieved in its free spectral range, and simultaneously get the best phase shiftcurve linearization. Numerical simulation and analysis is used in RF phase shift rangeand RF power of the designed microring resonator.